of karlstad



R. E. WAGNER. ROTARY PRESSmG APPARATUS FOR WOOD PULP AND CELLULOSE.

- APPLICATION FILED MAYIB, I919.

Patented Nov. 18, 1919..

UNITED STATES PATENT OFFICE.

RUDOLFERNST WAGNER, 0F KARLSTAID, SWEDEN, ASSIGNOR 'lIO AKTIEBOLAGETKARLSTAIDS MEKANISKA VERKSTAD, OF KARLSTAD, SWEDEN, A COMPANY OF SWEDEN.

ROTARY PRESSING APPARATUS FOR WOOD-PULP AND CELLULOSE.

Specification of Letters Patent.

Patented Nov. 18, 1919.

Application filed May IG, 1919. Serial No. 297,659.

To all whom it may concern: I

Be it known that l, RUDOLF ERNST WAG- NER, a subject of the King ofSweden, residing at Karlstad, in the Kingdom of Sweden, have invented anew and useful Improvementl, in Rotary. Pressing Apparatus for Wood-Pulpand Cellulose, of which the following is a specification.

. In rotary pressing apparatus for woodpulpand cellulose the upperroller of a pair of rollers} has heretofore as a rule been placedslightly in front of the lower roller in the direction of movement ofthe sheet of material or pulp sheet, and said sheet has been introducedbetween the rollers in such manner that it has first been applied to theupper roller in an inclined direction from a ove, and has followed saidupper roller to and past its lowest point, after which it has arrived tothe pressing place between the rollers, and afterward leftv the rollersin approximately tangential direction from the pressing place, that isto say obliquely up- Ward. This arrangement entails a ver essentialdisadvantage, however, particularly in such pressing apparatus in whichthe upper roller is provided with slots, grooves, or the like in itssurface, said disadvantage being that the water pressed out from thesheet of material by the upper roller and which accompanies said rollerin its direction of rotation, flows back downward along the surface ofthe roller and forms a body of water on the upper surface of the sheetof material behind the upper roller, on account of which'th greaterportion of said water will of course again be absorbed by the sheet ofmaterial and will accompany the sheet to the next pair of rollers wherethe course will repeat itself.

The present invention has for its purpose to obviate the saiddisadvantage, and it is broadly characterized by this that the upperroller provided with slots, grooves, or the like in its surface; islocated in such manner beyond the vertical plane through the lowerroller taken in the direction of movement of the sheet of material, andthat the sheet of the rollers that the surface of the upper roller fromthe pressing place in the direction-of rotation of the roller extendsdownward toward the lowermost point of the perlphery of the roller andsimultaneously diverges from the sheet of material. The stipulation thatthe upper roller is located beyond the vertical plane through the lowerroller is oflcourse only to be so understood that the axis of the upperroller is located It might perhaps appear to be the simplest solution ofthe problem of avoiding bodies of water on the upper surface of thesheet of material, entirely to give up the use of an upper roller and alower roller and insteadto use two rollers located on the same height,between which rollers the sheet of material is passed vertically fromabove downward, by which arrangement both rollers would be on a par withone another in respect of the possibility for an unchecked flowing offof the water. By practical tests, however, it has been established-thatthe flowing off of the water does not become more perfect in this mannerthan with the arrangement according to the present invention, in whichthe flowing off of water from the upper roller has proved to be quiteequal to that from the lower roller. Furthermore, such arrangement ofthe rollers is not practically feasible in pressing apparatus forwoodpulp and cellulose, owing to the fact that the placing of therollers beside one another would'require a too large space, and aboveall, on account of the fact that the sheet of material when passed undertension between the pairs of rollers is not capable of enduring thesharp turns in. which in suchcase it must be passed from a point beneatha pair of rollers to a point above the next pair of rollers. For thisreason and also on the ground that such rollers located on equal beenarranged in heretofore used pressing apparatus. Fig. 2 is a diagrammaticview showing the arrangement of press rollers according to the presentinvention. Fig. 3 shows to a larger scale a pair of press rollersiaccording to the present invention, in see- As illustrated in Fig. 1the upper roller has heretofore as a rule been located slightly in frontof the lower roller in the direction of movement of the sheet ofmaterial 1, and said sheet has been applied to the upper roller 2obliquely from above in order to effeet a kind of a pre-pressing of thesheet of material while said sheet bears against and accompanies theupper roller downward to and past its lowest point, after which saidsheet encounters the lower roller 3 at the pressing place 4:. From saidplace the sheet has heretofore been passed from the pair of rollers inthe direction of the common tangent through the pressing place, that isto say in a direction obliquely upward. In this manner the water pressedout by the upper roller at the pressing place, particularly when saidroller is provided with slots, grooves, or the like in its surface, andwhich water accompanies the surface of said roller from the pressingplace upward,

will afterward flow down and form a body of water at 5 on the uppersurface of the sheet of material between said sheet and the upperroller, on account of which, as stated above, practically all of saidwater will again become absorbed by the sheet of ma terial.

In the embodiment of the present invention diagrammatically illustratedin Fig. 2 the upper roller 6 which is provided with peripheral slots,grooves, or the like in its surface, is located beyond the lower roller7 in the direction of movement of the sheet of material or pulp sheet 8.The pulp sheet is preferably introduced between the rollers directly atthe pressing place 9 in the direction of the common tangent,consequently in an inclined direction from above, and it is led awaypreferably in the same direction, that is to say obliquely downward fromthe rollers. In this manner the surface of the upper roller from thepressing place 9 in the direction of rotation of the roller will bedirected downward toward the lowermost point 10 of the roller, as ismore clearly shown in Fig. 3, and the surface of the roller between thepoints 9 and 10 will diverge from the sheet of material and pass out ofcontact with the same. The water pressed out by the upper roller will bebrought along in the slots 11 in the surface of said roller, until ithas passed the lowermost point of the roller and afterward become liftedby the roller, when the water will flow off from the roller. In order tofacilitate the flowing off of the water there may suitably be providedat a point on the portion of the surface of the roller moving upward aso-called scraper 12 with knives 13 or the like projecting into theslots 11 of the roller. In order to collect the water from the upperroller 6 and prevent it from flowing back to the pulp sheet there isprovided a flute or trough 14 beneath the upper roller by means of whichtrough the water is led off toward the sides.

I'claim:

1. In a pressing apparatus for wood-pulp and cellulose, the combinationof a lower roller, and an upper roller provided with circumferentialslots in its surface and located beyond the vertical plane through saidlower roll-er in the direction of movement of the sheet of material.

2. In a pressing apparatus for wood-pulp and cellulose, the combinationof a lower roller, and an upper roller provided with circumferentialslots in its surface and located beyond the vertical plane through saidlower roller in the direction of movement of the sheet of material insuch manner that the surface of said upper roller from the pressingplace between the rollers in the direction of rotation extends downwardtoward the lowermost point of the periphery of said upper roller andsimultaneously diverges from the tangent through the pressing place.

3. In a pressing apparatus for wood-pulp and cellulose, the combinationof a lower roller, an upper roller provided with circumferential slotsin its surface and located beyond the vertical plane through said lowerroller in the direction of movement of the sheet of material, and ascraper bearing against the portion running upward of said upper roller.

4:. In a pressing apparatus for wood-pulp and cellulose, the combinationof a lower roller, an upper roller provided with circumferential slotsin its surface and located beyond the vertical plane through said lowerroller in the direction of movement of the sheet of material, and ascraper bearing against the portion running upward of said upper rollerand provided With knives projecting into the slots in said upper roller.

5. In a pressing apparatus for Wood-pulp and cellulose, the. combinationof a lower roller, an upper roller provided With circumferential slotsin its surface and located beyond the vertical plane through said lowerroller in the direction of movement of the sheet of material, a scraperbearing 10 against the portion running upward of said upper roller andprovided with knives projecting into the slots in said upper roller, anda trough beneath said upper roller.

BUD OLF ERNST WAGNER.

